1. Field of the Invention
The present invention relates to a camera capable of imprinting data such as time and date on a film.
2. Description of the Related Art
Conventionally, among cameras capable of imprinting data on a film, there exists a camera which allows to select a mode between modes for imprinting date data for indicating year-month-day and a day of the week and for imprinting time data for indicating day-hour-minute.
Further, among such cameras capable of imprinting data on a film, there is one that has a time piece circuit containing an oscillation circuit, divider, year-month-day calculating means independently beside a control circuit for controlling photographing of the camera. In such a case, two microcomputers for structuring the control circuit and the time piece circuit have to be provided within one camera, complicating the structure of the camera and bringing about a higher cost. Then, a camera has been proposed in which drive signal outputting means containing an oscillation circuit and dividing circuit outputs drive signals at certain intervals is contained in a control circuit comprising one microcomputer and a central processing unit (hereinafter referred to as a "CPU") is driven by the drive signal at the certain intervals to update time data (Japanese Patent Laid Open No. 3-140931 and others).
In such a case when such drive signal generating means is included to drive the CPU at certain intervals to update time data, the time data is always updated at intervals of imprintable minimum unit time. That is, in the prior art structure, the CPU has to be driven at least at intervals of one minute to update the time data, and in the example of the publication mentioned above, the CPU is driven at intervals of one second. However, because indicated data is actually changed once in 24 hours when the camera is set up in the mode for imprinting date data, the data needs not be updated at intervals of one minute and there is practically no problem even if the data is updated at longer intervals. Thus, the prior art camera consumes electric current more than it actually needs because it always drives the CPU at intervals of minimum unit time to update time data regardless of the modes of the data imprinting means and even when the main switch is switched off and the camera is in a state incapable of photographing.
Accordingly, it is an object of the present invention to simplify the structure and lower the cost of the camera capable of imprinting data by including drive signal generating means in the control circuit.
It is another object of the present invention to reduce the power consumption by appropriately changing updating intervals of time data.